Stock-feeding mechanism for automatic screw machines



Sept. 10, 1929. J. L. SCHMIDLING STOCK FEEDING MECHANISM FOR AUTOMATIC SCREW MACHINES Filed Aug. '7, 1924 Patented Sept. 10,1929. i 1,727,567

UNITED STATES PATENT OFFICE.

JOSEIT'H L. SCHMIDLING, F MILWAUKEE, WISCONSIN.

STOCK-FEEDING MECHANISM FOR AUTOMATIC SCREW MACHINES.

- Application filed August 7, 1924. Serial No. 730,695.

The invention relates to stock-feeding sectional view of a stock-feeding mechanism mechanism for automatic screw-machines. embodying the invention;

Th m kj di mechanism f t Fig. 2 1s a longitudinal sectional expanded matic screw-machines includes a feed chuck Vicwof the chuck members; which engages the stock to move it forwardly Fig- 3 IS an end View of the stock-clamping into a predetermined position where .it is l i gripped by a second chuck for subsequent tool If g- 4 I n end vlew of a similar member operations while the feed chuck is retracted adapted for El l c t S ape Of Stock. to a position for again advancing the stock In h d w gs, lndlcatcs a work spin- 10 t th proper moment i th cycle f Operadle which is yournalled in spaced bearings 11 60 tion. As heretofore constructed the feed h 2 and lsqphovldedht lts F 611d chuck has been Springmrged into engage with a chuck I for holding and rotating the ment with the stock at all times during both Shock 14 1h Ph adlace'nt Various 511C685- the feeding and retracting movements. W'ith slvely Opemhhg 15 this type f chuck the-clamping engagement A feed tube 15 s shdably mounted within 65 with the stock cannot be very tight since a sptndle to recelve the stock and 1s thread relative movement between fi chuck and ed at its forward end to receive the threadthe stock must Occur during the retracting ed end of a sleeve 16, so that the sleeve forms,

movement of the chuck. This uncertain en g f a q ti a 9 gagement with the stock causes a considerable ta g; 'iyf g 3?? g i gig g g 70 percentage of re cctedp1eces consequentnpon mgmber 9 is -y mounted Withinpth: fallure to feed the Sto-ck properly l-vhlch 1S bore and retained therein with one end ad- ?ggmvated by the rapld Wear Occurmg dur jacent the tapered surface by a threaded ing the slipping of the chuck over the stock bushino havin, a h eiving; head 75 on the retractmg movement necessltatmg 21. Th e bushing forms a stop limiting in one frequent Fenewal of the direction the short relative movement of the AI} Oblect of the h ih Is to sleeve and clamping member by its abutment Prhvlde f chuck Whlch i a g z h with an annularshoulder22 on the latter memgagement 9 during the mg her. The clamping member extends to the movement but Whlc 1 releasid from 6 outer end of the bushing 20 and is provided v1.3g engagement therewlth during the i p with longitudinalslots 23 extending from each mg m h thus .producmg i h end to afford spring fingers adapted to ensthckfeedlhg Operatlon and mlmmlzmg gage the stock when urged inwardly. This wearis accomplished by a tapered head 24 atone Another l h of the f E 15 f P end of the clamping member which when en e a :qhock'feedlhg mechhhlsm Whlch the gaging the tapered surface 17 of thesleeve chhck 1S controlled y the movements of the will press the fingers inwardly into clamping reciprocating feeding member in which the engagement with stock 40 Stock 15 Inserted and In operation, the feed tube 15, in which the A further Object of t e inve n is 0 P bar stock 1 is inserted, is moved forwardly vide a feed chuck in which the sto -cla p within the work spindle. During the initial mg member can be conveniently replaced y part of this movement the tapered surface 17 others for various sizes and shapes of stock i th l ls ngages with th tapered head and which can e r n wed at l w t. 24 of the stock-clamping member to bring The invention fur her con is s in e W- thelatter into firm engagement with the stock eral features hereinafter set forth and more hi h passes throu h it. The stock is then partlcularlv defined y Clalms at the Conchladvanced with the feed tube until it reaches S1011 heTeOfan adjustable stop 25, whereupon the chuck In the drawings: F1g.1 is a longitudinal 13 at the forward end of the work spindle is actuated by suitable mechanism to grip the stock in position to receive the tools. WVhile the stock is thus held in tool-receiving position, the feed tube is retracted. During the initial part of this movement the stockclamping member is released fromclamping engagement with the stock by the separation of the tapered surfaces of the sleeve and clamping, member, which permits the latter to slide relatively freely on the stock. The stock-clamping member is then moved by its abutment with the bushing 20 secured to the end of the sleeve as the feed tube is moved to its rearward position.

The stock-clamping or Work-receiving member is of simple and relatively inexpen sive construction, and as it becomes necessary to feed various sizes and shapes of stock the stock-clamping member may be readily replaced by another of suitable form, such as the one for square stock shown in Fig. 4:, by removing the threaded bushing 20.

It will thus be seen that the feed chuck o the present invention performs a positive stock-feeding operation but permits the stock-clamping member to slide freely over the stock when the feed tube is returning to its rearward position. A material reduction is thereby accomplished in the percentage of rejected pieces and Wear of the chuck is minimized.

What I claim as new and desire to secure by Letters Patent is:

1. In a device of the character described,

the combination of a reciprocable sleeve havmg a tapered surface therein, a tubular workreceiving member movable thereby but shiftably fitting therein for free movement and having longitudinally extending slots extending from its opposite ends and overlapping at an intermediate portion of said member to provide peripheral resiliency throughout its length and to form spring fingers, said work-receiving member being adapted by its engagement with the tapered surface of said reciprocable sleeve when said sleeve is moved relatively thereto in work-feeding direction to clamp the work and move it with said sleeve, and said Work-receiving member being releasable from its clamping engagement with the work by the relative movement of said sleeve with respect to said work-receiving member during the retraction of said sleeve.

2. In a device of the character described, the combination of a reciprocable sleeve having an interiorly-threaded end and an interior tapered surface spaced from said end, a

tubular work-receiving member movable by said sleeve but shiftably fitting therein for free movement and forming work-engaging spring fingers having tapered portions engageable with said tapered surface, there being a shoulder disposed at an intermediate. portion of said work-receiving member, and

a bushing disposed Within the threaded end of said sleeve to form a stop engageable by said shoulder and having an interior cylindrical surface forming a guide for the end of said work-receiving member, said work-receiving member being adapted by its engagement with the tapered surface of said reciprocable sleeve when said sleeve is moved relatively thereto in work-feeding direction to clamp the Work and move it with said sleeve, and.'said work-receiving member being releasable from its clamping engagement with the work by the relative movement of said sleeve with respect to said work-receiving member during the retraction of said sleeve. In testimony whereof, I affix my signature.

JOSEPH L. SCHMIDLING. 

